A request is made for a shared instrumentation grant to NCRR for a Micromass hybrid quadrupole time of flight (Q ToF) mass spectrometer. The instrument will be housed in the Center for Integrated Genomics (CIG), a new research unit on the Berkeley campus. The instrument will be used for protein identification following one- or two-dimensional gel electrophoresis, using MS-MS sequencing of proteolytic peptides. Projects supported by this instrument will involve human and Tetrahymena telomerase, Drosophila, Ciona and Artmia transcription factors, Drosophila P element transposase and DNA repair proteins, Drosophila RNA binding / RNA splicing factors and Xenopus embryonic transcription and signal transduction factors. The instrument will also be used to analyze protein phosphorylation of transcription factors, DNA recombination enzymes, telomerase and RNA splicing factors using nano-LC MS-MS and precursor ion scanning in the positive or negative mode. An instrument of this type, using nano-elctrospray ionization in conjunction with a hybrid quadrupole-time-of-flight mass analyzer is not available on the U.C., Berkeley campus.